A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Original seamless pattern with an Inkscape filter.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Kaleidoscope Prismatic Abstract No Background
Source GDJ
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
The image is a seamless pattern of a fishnet.
Source Yamachem
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Prismatic Abstract Background Design No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Abstract Tiled Background Extended 6
Source GDJ
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
If you want png files of thisu can download them here :
Source Viscious-Speed
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso